Centralized electronic systems, such as a communication network system or a parallel computer processing system, employ a variety of electronic devices residing in a housing or other suitable enclosure. One type of electronic device included in such systems is the front end rectifier.
The front end rectifier converts alternating current (AC) power into an intermediate direct current (DC) power/current/voltage. Power is received from the AC distribution system, which may be, for example, provided at 120 volts AC or 240 volts AC. An electronic rectifying device residing in the front end rectifier converts the received AC power (AC current and AC voltage) into DC power (DC current and DC voltage). Intermediate DC voltage may be, for example, at 48 volts or 12 volts DC, though any suitable intermediate DC voltage may be used depending upon the system design.
Intermediate DC power/current/voltage is used to provide power to individual devices in the electronic system. However, the electronic devices typically require a different DC voltage for operation, so further DC/DC voltage transformation is required, performed by a DC/DC converter output module. The total amount of DC power required by the electronic system is determined, in part, by the loading requirements of all components in the system.
Determining power consumption in the front end rectifier(s), the DC/DC converter output modules and the electronic devices is problematic. Typically, actual energy and demand, in the aggregate or for individual components residing in the enclosure, cannot be determined because such information is not metered. Rather, estimates of energy and demand are used. Such estimates may be based upon known design parameters and/or prior testing of similar devices. However, estimations do not provide precise or reliable information on the actual energy and demand of individual components residing in the enclosure.
Alternatively, an external metering system may be coupled between the enclosure and the AC power supply such that actual energy and demand are monitored on a real time basis. However, this technique may not provide information regarding actual energy and demand by individual components residing in the enclosure. And, with the metering equipment being outside of the enclosure, it may be subject to accidental damage, theft or the like.
One significant problem encountered with conventional electronic systems is that the size, orientation and location of individual components residing in the enclosure are based upon tight design tolerances. That is, components are designed to closely fit next to each other so that a minimum amount of enclosure space is required. Accordingly, it is very difficult to later add metering equipment, and their associated connections, to meter energy and demand within the enclosure. Furthermore, later addition of metering equipment may raise safety and reliability issues. For example, connecting meter leads to components in the enclosure may be dangerous for the test personnel. Also, if an accident were to happen, equipment within the enclosure may become damaged. It is possible that the entire electric system may become inoperable.
Another significant problem relating to the ability to accurately monitor and/or determine actual energy and demand is that in some enclosures, multiple front end rectifiers are used to convert the AC power into DC power. When multiple front end rectifiers are coupled in parallel to the AC power system, actual loading through individual front end rectifiers is not precisely known. For example, slight variations in impedances between individual front end rectifiers will result in imbalanced loading conditions. That is, a slightly lower impedance front end rectifier may be more heavily loaded than a higher impedance front end rectifier. Minor impedance differences may occur between identical models of front end rectifiers. Or, impedance differences may arise if different models of front end rectifiers are used, especially if the front end rectifiers are manufactured by different vendors using different design criteria and different components.
Or, if the front end rectifiers operate with similar components, such as when identical models are used, slight loading imbalances may still occur due to the inherent differences resulting from manufacturing tolerances of individual elements in the control system. Thus, precise determination of actual power (energy and/or demand) flowing through individual front end rectifiers can not be made even if identical front end rectifiers are used in the enclosure.
Additionally, various types of electronic systems have complex processing systems. One example is a server system that employs a memory system for control of switching devices. Various control algorithms used by the server processors to access the memory system are based upon memory access control algorithms. These memory access control algorithms can be adjustable or modifiable to change the type of memory access and/or the frequency of memory access by the processors.
Accordingly, changes or modifications to the memory access control algorithms may change power consumption within the server system. However, outside of lab conditions where bench testing and power metering is easy to implement, determining changes in power consumption when the memory access control algorithms are changed or modified in the field is very difficult.
Furthermore, various design changes, component changes and/or control algorithm adjustments may be made to other components of a server system over time. For example, the vendor of a selected component might be changed such that earlier models of the server system have the selected component from the first vendor, and later models have the selected component from the later vendor. Or, the design engineer may want to make adjustments to the control algorithms and would like to know the impact of the changes in energy and/or demand. Accordingly, it would be very beneficial to have a convenient and accurate way to monitor changes in energy and demand in an individual front end rectifier and in a server system.